A main task of the committee was to examine the evidence related to claims of positive and negative effects of existing genetically engineered (GE) crops. The committee delved into the relevant literature, heard from 80 diverse speakers, and read more than 700 comments from members of the public to broaden its understanding of issues surrounding GE crops. The Committee concluded, among other things: that 1) The available evidence indicates that GE soybean, cotton, and maize have generally had favorable economic outcomes for producers, but that outcomes have been heterogeneous, 2) The crops with the insect-resistant trait generally decreased yield losses and the use of insecticides, 3) In some cases, widespread planting of those crops decreased the abundance of specific pests 4) In locations where resistance management strategies were not followed, damaging levels of resistance evolved in some target insects, 5) Herbicide-resistant (HR) crops often had small increases in yield, 6) Farm-level surveys did not find lower plant diversity in fields with HR crops, 7) in areas where planting of HR crops led to heavy reliance on a herbicide, some weeds evolved resistance and present a major agronomic problem, and sustainable use of Bt and HR crops will require use of integrated pest-management strategies, 8) The large number of experimental studies available provides reasonable evidence that animals were not harmed by eating food derived from GE crops, 9) Long-term data on livestock health before and after the introduction of GE crops showed no adverse effects associated with GE crops, 10) epidemiological data showed no substantiated evidence that foods from GE crops were less safe than foods from non-GE crops, 11) GE crops have benefited many farmers on all scales, but genetic engineering alone cannot address the wide variety of complex challenges that face farmers, especially smallholders, 12) Molecular biology has advanced substantially since the introduction of GE crops two decades ago. Emerging technologies enable more precise and diverse changes in crop plants. Resistance traits aimed at a broader array of insect pests and diseases in more crops are likely, 13) Research to increase potential yields and nutrient-use efficiencies is underway, but it is too early to predict its success. The committee recommends a strategic public investment in emerging genetic-engineering technologies and other approaches to address food security and other challenges, 14) Omics technologies enable an examination of a plant’s DNA sequence, gene expression, and molecular composition. They require further refinements but are expected to improve efficiency of non GE and GE crop development and could be used to analyze new crop varieties to test for unintended changes caused by genetic engineering or conventional breeding, 15 ) National regulatory processes for GE crops vary greatly because they mirror the broader social, political, legal, and cultural differences among countries. Those differences are likely to continue and to cause trade problems. 16) The committee recommends that new varieties—whether genetically engineered or conventionally bred—be subjected to safety testing if they have novel intended or unintended characteristics with potential hazards.
The full pre-publication report can be obtained here: